BUFFALO, N.Y. – How do the lungs of e-cigarette users
differ compared to non-smokers and people who smoke traditional
cigarettes?

A pilot study awarded to a University at Buffalo epidemiologist
seeks to provide some answers to that question. It’s a
question that’s taken on greater significance as more people
use e-cigarettes, and as the U.S. Food and Drug Administration has
assumed regulatory control over them.

“E-cigarette use is increasing rapidly, including among
young people who never smoked cigarettes,” said Jo
Freudenheim, UB Distinguished Professor and chair of epidemiology
and environmental health in UB’s School of Public Health and
Health Professions.

Freudenheim, PhD, is the principal investigator on the $100,000
grant from the Prevent Cancer Foundation, the only U.S. nonprofit
organization solely devoted to cancer prevention and early
detection.

Research on the effects of e-cigarettes is critically important
given the lack of knowledge about the health impacts to users.

“There’s a lot of interest in understanding how
e-cigarettes affect the body,” Freudenheim said. “The
FDA, in particular, is very interested in data about the biological
impact of e-cigarettes. This study will contribute to that.
It’s only one piece of a puzzle, but it’s a potentially
important piece.”

The predominant ingredients in e-cigarette liquids — often
called “e-juice” — are nicotine, propylene glycol
and/or glycerol. When used in food and cosmetics, the non-nicotine
constituents are considered safe by the FDA. However, there is
little knowledge on how these ingredients and their by-products
affect human lungs when inhaled following the heating and
aerosolizing process that takes place in e-cigarettes.

For this pilot study, Freudenheim and her colleagues will
examine samples from the lungs of healthy smokers, non-smokers and
e-cig users, aged 21 to 30. The study participants underwent a
procedure called a bronchoscopy, where a sample of lung cells were
collected by a rinse procedure.

The investigators are studying whether there are differences in
DNA methylation among the three groups. They will study 450,000
spots on the tissue DNA.

“Every cell in your body has the same DNA, but some parts
of that DNA are turned on in different tissues — for example,
for one cell to become a hair cell instead of a stomach or lung
cell. Changes in DNA methylation contribute to allowing for those
different kinds of cells,” Freudenheim explains.

“In tumors, one of the things that can happen is that DNA
methylation can go awry — something that’s not supposed
to be turned on is turned on or turned off when it should be turned
on. We know that there are these kinds of changes in lung cancers
and also that some of these differences in DNA methylation are seen
in apparently healthy smokers. The point of this study is to find
out how the DNA methylation in e-cigarette users compares to the
other two groups,” she said.

Freudenheim’s study will build off of another pilot study
recently begun by Peter Shields, MD, of The Ohio State University
College of Medicine, a co-principal investigator on the Prevent
Cancer Foundation grant. The goal is eventually to apply for
funding for a larger study.

Min-Ae Song of The Ohio State University is a co-investigator.
Dominic Smiraglia, PhD, associate professor of oncology at Roswell
Park Cancer Institute in Buffalo, is a consultant on the UB
study.

Freudenheim
has long been interested in DNA methylation, focusing mostly on
breast tumors, while Shields has extensive experience researching
tobacco and e-cigarettes. They have collaborated for more than 20
years on research regarding ways to prevent cancer.